If you are new to WP, chances are that you will have issues with your site. Do not panic, you can ask for help or google the exact problem/error you have, most of the times you will find many resources with fixes. From my experience 90% of the cases can be diagnosed easily though.
First things to try :
- Disable any caching/optimization plugins, clear your browser’s cache!
- Disable all your plugins or the ones you do not need to view/use your site.
- Switch to one of the default WP themes ( twenty fifteen, twenty nineteen etc)
If you do these and still have the same problem, like not able to view your site or create a post, here are more advanced ways to find the problem.
If again you cannot find the culprit it is better to hire a professional : )
tip: always work on a staging site!